1. Field of the Invention
The present invention relates to a driver assembly for solid state lighting wherein the driver assembly is substantially compact and efficient so as to achieve a variety of uses, can achieve a varied range of power outputs without overheating, and is sufficiently contained so as to be usable in a setting wherein an explosion proof fixture is necessary.
2. Description of the Related Art
Solid state lighting, and in particular the powering and use of LEDs for lighting is becoming increasingly popular as a highly efficient and energy conscious form of illumination that can be used in a number of different applications to replace traditional incandescent or fluorescent lighting. A significant problem associated with the use of solid-state lighting, however, relates to complications that arise in connection with the driver that is utilized to power the LED light. Specifically, because LED lights operate at lower voltages than are traditionally supplied in most operative environments, a driver is necessary to properly manage the load and effectively supply the needed low voltage power to the LED. As part of this power management and control process, however, the drivers are particularly susceptible to overheating given the nature of the components and the manner in which they are being utilized.
Further, overheating does not merely cause a problem within the context of generating unwanted heat into an environment, but is especially problematic in sold state lighting as it can lead to failures in one or more components of the driver, and thus a malfunction or shut down of the entire system. For this reason, most typical solid state drivers include some form of heat sink to draw heat away from the driver. Unfortunately, however, inefficiencies in the configuration and design of the operative circuitry of traditional drivers and heat sinks still result in greater than optimal levels of failure, and require that the drivers and heat sinks be substantially large so as to effectively manage the heat by providing a large surface area from which the heat can be dissipated. This is especially the case at larger power outputs such as those that might be necessary for room lighting, and even more significantly for the lighting of large spaces. As a result, LED based solid state lighting has seen limited applicability where a substantial amount of light is needed. Further, when attempts have been made to provide greater illumination using LEDs, illumination systems with large driver bars and heat sinks must typically be employed so as to provide a large surface area for heat dissipation, thus requiring a large mounting surface and a larger footprint than may be optimal.
A further significant limitation associated with the field of solid-state lighting relates to the inapplicability of cost effective solid-state lighting in a variety of environments and in particular environments wherein all lighting and fixtures must be explosion proof. Specifically, in certain environments where flammable gases and other materials may be present, all devices and systems present in the area are required to be explosion proof. This means that all components must be properly insulated so that no external sparks or explosions can affect the area and possibly ignite the flammable conditions that could exist in the environment. Because of the nature of traditional solid-state driver assemblies, there is always some risk of uncontainable sparks or explosions at the driver, and the large size of traditional driver assemblies makes it impractical to properly address this risk.
Another factor that often leads to the requirement that a solid-state driver have a substantially large size, thereby making it impractical for a variety of applications, relates to the risk of magnetic interference and more particularly cross coupling between components such as the input and output inductors. Specifically, magnetic cross coupling results in a state wherein even when the power to the output inductor is intended to be turned off, cross coupling to the powered input inductor will still result in power at the output inductor. As a result, traditional solid-state driver assemblies require that the input and the output inductors be placed in substantially spaced apart relation from one another. Of course, because of the already present requirement for a large surface area in order to effectively dissipate heat, the large spacing necessary is often available to allow for this effective separation, and no alternate solution has been contemplated. As a result, this provides yet another reason to require larger sized driver assemblies that in turn limit the applicability of the solid-state lighting to environments that can accommodate a larger fixture and driver assembly, and that can accommodate the larger material and installation costs associated with larger footprint driver assemblies.
Still another drawback associated with traditional solid-state driver assemblies relates to the ever increasing need for power output customization. Specifically, as more and more applications for LED lighting are designed and developed, a variety of different, but often very precise power outputs are required. For example, a particular lighting application may require a very precise output wattage be maintained in order to achieve proper compliance of a fixture or device in which the LED light source is utilized. Accordingly, modification and reconfiguration of the driver assembly to achieve this desired customized power output, and pre-programming of components, is often required. This need for customization, however, further limits the applicability of traditional driver assemblies and increases the costs associated with their use. For example, manufacturers of the driver assemblies are not in a position to manufacture large volumes of different configuration driver assemblies to maintain an effective stock. Rather, they typically keep smaller fully fabricated inventories and instead maintain separate components that cannot be finally assembled until they receive an order and are aware of the precise required specifications. Further, this limitation not only increases the costs associated with the manufacture of the drivers and the maintaining of uncompleted inventory, but also limits the effective applicability of the driver assemblies as the drivers cannot be pre-prepared for certain environments, such as an environment that requires an explosion proof driver assembly or a weather resistant driver assembly.
Accordingly, there is a substantial need in the art for a compact and highly efficient solid-state driver assembly which is able to achieve a substantially small and compact operative footprint, while still allowing for effective heat dissipation in order to minimize the potential for failure or malfunction of the driver assembly. Also, there is a substantial need in the art for a compact and efficient driver assembly that can be utilized in a variety of applications, including applications wherein an explosion proof and/or weather or waterproof fixture is necessary, while still allowing for substantially customizability in terms of power output even after manufacturing and product assembly.